1. Field of the Invention
The present invention relates to semiconductor apparatuses and fabricating methods, fabricating apparatuses, circuit boards and electronic devices relating to the same.
2. Description of Related Art
As one type of packages for semiconductor devices, QFP (Quad Flat Package) in which a semiconductor chip is mounted on a lead frame is known. More specifically, a semiconductor chip is mounted on a die pad of a lead frame, and electrodes of the semiconductor chip are wire-bonded to leads of the lead frame. Also, the entire semiconductor chip is covered by a resin. It is noted that lead frames are often made from copper.
In general, in the wire-bonding process, a lead frame that mounts a plurality of semiconductor chips is transported and the bonding is performed over heat sections that are heated at high temperatures over 200xc2x0 C. More specifically, the heat sections are provided at a bonding stage where the wire-bonding is performed and a stand-by stage where the die pads of the lead frame are held before being transferred to the bonding stage. In the stand-by stage, the lead frame is brought in contact with the heat section and heated.
Therefore, since the lead frame is heated not only in the bonding stage for the wire-bonding work but also in the stand-by stage, oxide films would be formed on the lead frame after the bonding process is completed. The oxide films could deteriorate the adhesion of the resin that seals the lead frame and the semiconductor chip, and could lower the reliability of the semiconductor device.
The present invention solve the problems described above, and it is an object of the present invention to provide a reliable semiconductor device and a manufacturing method, a manufacturing apparatus, a circuit substrate and an electronic apparatus relating to the same by suppressing the oxidation of a lead frame to thereby improve the adhesion of resin with the lead frame.
(1) A method for manufacturing a semiconductor device in accordance with the present invention may include the steps of:
disposing a lead frame having a plurality of die pads on which semiconductor chips are respectively mounted in a bonding apparatus, and wire-bonding electrodes of the semiconductor chips and leads of the lead frame, wherein the bonding apparatus includes a bonding stage and a stand-by stage, and a heat section is provided at least in the bonding stage among the bonding stage and the stand-by stage,
disposing at least one of the die pads of the lead frame in the bonding stage and the remaining die pads in the stand-by stage, and
placing the die pads disposed in the stand-by stage in a non-contact state with the heat section, while the die pad disposed in the bonding stage is brought in contact with the heat section to be heated and wire-bonded.
In accordance with the present invention, while the die pad disposed in the bonding stage is wire-bonded, the die pads in the stand-by stage are placed in a non-contact state with respect to the heat section. In other words, the heat of the heat section for wire-bonding can be prevented from being directly applied to the lead frame that is placed in the stand-by stage. As a result, for example, the growth of an oxide film that may be formed in rear surfaces of the die pads of the lead frame can be suppressed, and the adhesion between the rear surfaces of the die pads and the resin can be improved. Accordingly, highly reliable semiconductor devices can be manufactured.
(2) In the method for manufacturing a semiconductor device, side sections of the lead frame may be supported, and the die pads placed in the stand-by stage may be placed in a non-contact state with the heat section.
As a result of supporting the side sections of the lead frame, the die pads in the stand-by stage are placed in a non-contact state with the heat section, while the die pad placed in the bonding stage is bonded. Therefore, the growth of oxide films that are formed on the rear surfaces of the die pads can be suppressed, and highly reliable semiconductor devices can be,manufactured.
(3) In the method for manufacturing a semiconductor device, the lead frame can contain copper.
(4) A semiconductor device in accordance with the present invention is manufactured by the above-described method for manufacturing a semiconductor device.
(5) A circuit substrate in accordance with the present invention has the above-described semiconductor device mounted thereon.
(6) An electronic apparatus in accordance with the present invention includes the above-described semiconductor device.
(7) A manufacturing apparatus for manufacturing a semiconductor device in accordance with the present invention includes:
a bonding stage for wire-bonding electrodes of semiconductor chips mounted on die pads of a lead frame with leads of the lead frame; and
a stand-by stage for, while at least one of die pads of the lead frame is wire-bonded in the bonding stage, disposing the remaining die pads of the lead frame,
wherein a heat section is provided at least in the bonding stage among the bonding stage and the stand-by stage, and the heat section may be provided in a manner that it is placed in a non-contact state with the remaining die pads of the lead frame disposed in the stand-by stage, when the heat section contacts the at least one of the die pads of the lead frame disposed in the bonding stage.
In accordance with the present invention, the heat section is provided in a manner that it is placed in a non-contact state with the die pads disposed in the stand-by stage, when it contacts the die pad disposed in the bonding stage. In other words, while the die pads placed in the bonding stage are brought in contact with the heat section to be heated and wire-bonded, the die pads placed in the stand-by stage are brought in a non-contact state with the heat section. As a result, the heat of the heat section for wire-bonding can be prevented from being directly applied to the lead frame that is placed in the stand-by stage. As a result, for example, the growth of an oxide film that may be formed in rear surfaces of the die pads of the lead frame can be suppressed, and the adhesion between the rear surfaces of the die pads and the resin can be improved. Accordingly, highly reliable semiconductor devices can be manufactured.
(8) In the method for manufacturing a semiconductor device, the heat sections are provided in the bonding stage and stand-by stage, wherein the heat section may be provided with a surface thereof opposing the lead frame in the stand-by stage being lower than a surface thereof opposing the lead frame in the bonding stage.
As a result, the heat of the heat section for wire-bonding can be prevented from being directly applied to the lead frame that is placed in the stand-by stage. As a result, for example, the growth of an oxide film that may be formed in rear surfaces of the die pads of the lead frame can be suppressed, and the adhesion between the rear surfaces of the die pads and the resin can be improved. Accordingly, highly reliable semiconductor devices can be manufactured.